This document contains final and temporary regulations relating to the requirement, added by the Protecting Americans from Tax Hikes Act of 2015, that organizations must notify the IRS of their intent to operate under section 501(c)(4) of the Internal Revenue Code (Code). The regulations affect organizations described in section 501(c)(4) (section 501(c)(4) organizations) that are organized after December 18, 2015, and certain section 501(c)(4) organizations existing on that date. The text of the temporary regulations serves as the text of the proposed regulations set forth in the related notice of proposed rulemaking (REG-101689-16) published in the Proposed Rules section in this issue of the Federal Register.